(i) Technical Field
A certain aspect of the embodiments discussed herein is related to a method for fabricating a semiconductor device.
(ii) Related Art
Nitride semiconductors are used for power devices capable of operating at high frequencies and outputting high power. An electrode formed on a nitride semiconductor layer is an ohmic electrode for making a good electrical contact (see Japanese Patent Application Publication No. 2006-173386.
High-power devices using nitride semiconductors are required to have a small contact resistance of the ohmic electrode in order to improve the power efficiency. The contact resistance may be reduced by forming the ohmic electrode in a recess formed in the semiconductor nitride layer. However, in a case where the recess is formed by etching, the bottom of the recess may get rough. The rough bottom of the recess increases the contact resistivity of the ohmic electrode.